Cutter.



F. RICHARD.

CUTTER.

APPLICATION FILED 0:015. 1914.

Patented Oct. 16, I917.

2 2255555: 4 lzmmfm.

s'rans respects steam; or

CLEVELAND, OHIO, ASSIGNOR TO THE RICHARD AUTO MFG.

COMPANY, OF CLEVELAND, OHIO. V

negates.

Specification of Lettersjatent.

Patented Get. 1%, 191?.

Application filed December 15, 1914. Serial No. 877,327.

To all whom it may concern:

Be it known that I, FnAngors RICHARD, a citizen of the French Republiqresiding at Cleveland, in the county of Cuyahoga and State of Ohio, have invented a new and usefnl Improvement in Cutters, of which the following is a specification, the principle of the invention being herein explained and the best mode in which I have contemplated applying that principle, so as to distinguish it from other inventions. v My invention has -general reference to cutters and more particularly to rotary cutters such as are employed for boring; milling, facing, reaming, and end-mill work.

Figure 1 Ba perspective view of a cutter head carrying a number of cutting knives after the manner of my invention.

' Fig. 11 is an end elevation of Fig.1. Fig. H1 is a bottom plan of Fig. ll. Fig. 1V is a plan of the cutting face of one of the hives.

Fig. V is a rear plan of Fig..IV.

W is a section on line VI-Vl of Figi 7 Directing attention to the several views, a

cylindrical cutter head 1, having a spindle hole 2 and flat sides 3 is furthermore provided as is customary, with circumferentially arranged peripheral slots 4: which open through both of the sides 3. The slots 4 not only extend obliquely across the cutter head "but. are furthermore purposely sloped rearwardly with reference 'to the proposed direction of rotation of the cutter head as they proceed inwardly.

A corresponding number of knives 5 are seated as a mechanical fit in the slots 4 and held in correct position up and down in the well known manner as with pins 6 passing through suitable openings. As a necessary incident, the outwardly projecting portion of each lmife is tilted forwardly as is perhaps most clearly seen at the top of Fig. Ill. Mention is made that the degree of tilt is quite arbitrary and ordinarily would vary according to the character of workto be performed. Each of the knives is pro- 1 vided with a cutting edge 7 extending across the periphery of the cutterhead and-rearwardly of such edge is provided with a beveled outer surface 8 to provide the necessary clearance. The cutting edges 7 are those which are employed for facing, milling, and reaming, but owing to the fact that such cutting edges are more advanced than any other line in the cutting face 9 which extends across the cutterhead, the cuts effected thereby are shearing or proper shaving cuts rather than scraping cuts. Each of the knives 5 is furthermore provided underneath with a cutting edge 10 extending rearward'ly with reference to the direction of rotation as well as inwardly whereby if the lineof such cutting edges 10 were continued they would subtend arcs less than 180 and such arcs would be rearwardly of the point of intersection of the plane of the cutter face with the periphery of the cutterhead.

conversant with this art that during a. boring operation, the meeting points of the cutting'edges 7 and cutting edges 10 become subject to very severe usage. With this in mind I have cut oif those corners which would ordinarily be the junctions of the cutting edges 7 and the cutting edges 10. Thisl have done at an angle of to form surfaces 12, as seen in Fig. V. It should be understood however, that such angle is by no means necessarily fixed at 45. The cutting. face 9 is fastened just back of the corner surface 12 with a groove 13 as.

is clearly shown in Figs. IV and VI. The purpose of this groove is to provide a third edge 14 which is necessarily,-in accordance with this exemplification, at an angle of 67 1- degrees to each of the cutting edges 7 and 10. I have discovered that such an additional cutting edge disposed at various angles to both of the other cutting edges produces a very marked improvement as regards both speed and quality ofboring cut.

I claim: 1. A cutter having a pair of angularly disposed cutting edges and a corner cutting edge connecting the others, said knife being fashioned with e groone having one side merging along said corner edge and inter seating said other two edges.

2. A cutter head carrying a forwardly 1 tilted knife having three angularly related neeegeee middle one of said edges whereby to accentuate the same Signed by me, this 11th day of Decem leer, "19M. 7

' FRANQOIS RICHARD. Attested by F. M. BRADY, C. E. MnnnocK. 

